Motor-cylinder and process of making same



E. E. ALLYNE AND J. W. COLLINS. I MOTOR CYLINDER AND PROCESS OF MAKING SAME.

APPLICATION'HLED JUNE 12. ms. Patente y 1920 2 SHEETSSHEET Faint *5: N I I. L L 6 W E. E. ALLYNE AND J. w. COLLINS. MOTOR CYLINDER AND PROCESS OF MAKING SAME. APPLICATION FILED JUNE 12, I916- 1,34:7,477. Patented July 20, 1920.

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EDMUND E. ALLYEE, or CLEVELAND, 01110, AND JOHN WESLEY COLLINS, 0E DETEQI MICHIGAN, AssIGNoEs To THE ALUMINUM CASTINGS COMPANY, 01? CLEVELAND, 01110, A oo ronATIoN OF OHIO.

MOTOR-CYLINDER AND PROCESS OF MLAKJIIN'G' SAME.

Specification of'Letters Patent.

Patented July 20,1920.

Application med June 12, 1916. Serial No. 103,136.

T 0 all whom it may concern: 7

Be it known that we, EDMUND E. ALLYNE and JOHN W. COLLINS, citizens of the United States and Canada, respectively, residing at Cleveland, countyof Guyahoga, and State of Ohio, and Detroit, county of Wayne, and State of Michigan, respectively, have invented certain new and useful Improvements in and Relating to Motor-Cylinders and Processes of Making Same, of which the following is a specification. :This invention relates to a process of making motor cylinders, more particularly cylinders for use in internal combustion motors of the reciprocating piston type, and also to the cylinders themselves.

One object of the invention is to provide a process of making such a motor cylinder or cylinders of composite structure and relatively light weight, without sacrificing either strength, 'durability or thermodynamic efliciency.

Another object of the invention is to provide an improved process of making such a motor cylinder with improved heat dissipating' characteristics and also one in which there will be where desired substantially uniform expansion of the cylinder walls immediately to be traversed by the piston, thereby reducing to a minimum frictional resistance between the cylinder walls and piston.

Another object of the invention is to provide an improved process of making such a cylinder from which, relatively high thermal and mechanical efiiciencies may be obtained with elimination of practically all troubles incident to overheating and unequal heat expansion of the cylinder walls.

Another object of the invention is to provide a process of making such a cylinder having a liner of iron or other suitable material which resists wearand forms a good bearing surface, wherein intimate and uniform contact is provided at all desirable points between the outer walls of the liner and the inner walls of the cylinder or supporting structure, in order to avoid air gaps or spaces where not desired on the one hand, and on the other to provide efiicient transmission of heat at all points circumferentially of the cylinder throughout the length of the cylinder traversed by the piston.

Another object of the invention is to provide an improved process of making such a cylinder the walls of which may be readily and accurately ground or machined to provide a smooth surface capable of receiving and uniformly engaging the external walls of a liner where desired.

Another object of the invention is to provide a process of making such a cylinder having a liner of iron or other suitable material of substantially uniform cross-section at any point of its length to be traversed by a plston, the inner walls of which cylinder are substantially non-porous and relatively fine grained'to facilitate proper machining and eflicient heat transmission where desired, and to provide against leaks from the water jacket inwardly.

Another object of the invention is to provide an improved process by which such a cylinder having relatively fine grained, substantially non-porous walls may be made from aluminum and other metallic alloys of relatively low specific gravity and relatively high coefficient of heat conductivity and ex- With these and other objects in view, the

invention consists of steps hereinafter described and the resulting product, selected for the purpose of illustration.

First, we cast from an aluminum alloy a cylinder section or a plurality of cylinder sections en bloc, in a mold, the core or cores of which are chilling cores.

Preferably the casting is made with a water jacket formed around each cylindersection. The chills are preferably formedirom aluminum and may be of sectional character and separated from each other to provide between. them sand spaces through which the air and gases freely escape. As a result of this chilling action. the metal of the inner walls consti- 'tuting the cylinder or cylinders, as compared with the metal of the unchilled walls,

is relatively fine grained, non-porous and impervious to cooling fluids, harder, easier to machine and has smoother surfaces.

"The casting having cooled, we next shape the inner walls 'of each aluminum cylinder section to substantially cylindrical form. We have found that the relatively fine grained structure of the cylinder section or sections greatly facilitates the proper and accurate shaping or conditioning of the inner walls of each cylinder section, which .metal,-for each cylinder section. In the construction of the liner, provision must be made for the expansion of the piston and cylinder walls with which it engages, which expansion -is due to the high heat generated by the burning of combustible gases within the motor cylinders of this type. If. the cylinder walls with which the piston engages are substantially homogeneous in texture and material and are of substantially uniform cross-section at all portions of piston travel, the expansion effect of heat will be substantially uniform on the metal of the cylinder at any cross-section and mechanical frictional losses due to distortion of the cylinder wall reduced to ,a minimum.

. With this purpose in view we provide a tubular liner or inner wear resisting cylinder, which may be drawn or surfaced in any suitable manner to accurate internal and external diameters, and thereby insure practical uniformity of cross-section at any point and of structure of material throughout the length of said liner to'be traversed by the piston. The exterior diameter of the liner should be such that when the liner is positioned in the finished aluminum cylinder section the interior walls of the aluminum cylinder and the exterior walls of the liner will be-in snug engagement or intimate contact with eachother circumferentially, where desired, and particularly at the end of the piston stroke, where it is desired rapidlyand efficiently to transfer heat to the water jacket or aluminum wall surrounding the liner. As the walls of the liner, which are subjected to strains and stresses, are to be suitably supported at all points circumferentially-where desired, they may be relatively thin and light weight and, without prohibitive cost, constructed of a much higher grade of material than cast iron cylinders, thus insuring that the cylinder walls'which immediately confine the gases of combustion and are engaged by the piston will be of substantially homogeneous metal throughout their length traversed by the piston. When this cylinder is supported in position in the cylinder section or outer cylinder of cast aluminum alloy metal which has higher co-efficients both of heat con ductivity and expansion than the metal of the inner cylinder or liner, the heat to be transferred from the inner cylinder to the cooling circulating fluids is conducted away with greater rapidity and efficiency than is now possible with cast iron cylinders. Furthermore, since the inner cylinder wall of the casting is non-porous and the surface smooth, the engagement between it and the outer wall of the liner may be made relatively eificient for the transfer of heat where desired, and particularly at the end of the piston stroke when it is desired to transfer heat as rapidly and efliciently as possible. Were the inner wall of the cylinder casting porous, the presence of blow-holes or cavities in the casting would tend materially to interfere with the eflicient and uniform transfer of heat.

Such a'liner is then inserted in each aluminum alloy cylinder section in any suitable way butadvantageously by forcing it into place through the open upper end of the cylinder. 7 The insertion of the liners is done. preferably at normal atmospheric temperature so that there is no possibility of their being warped, distorted or gotten out of shape by being subjected to high temperatures, such for example a those to which it would be necessary to subject them were molten aluminum or alloy cast about the relatively thin liners to form exterior cylinder walls and water jackets. After the liners have been inserted there is no need of resurfacing their inner walls with which the pistons engage because of any conditions to which such walls are subjected'in getting the liners into the tubular aluminum sections.

We may removably secure the liner in position relative to the aluminum cylinder section in any suitable way, but preferably we provide the liner at one end with a boss or flange which we seat in a corresponding recess in the adjacent surrounding aluminum cylinder section. This boss or flange may be engaged and held in place against axial movement outwardly by the cylinder head which may be suitably shaped for the purpose and removably secured to the aluminum casing in any well known manner.

As the coeflicient of expansion of aluminumis greater than thathaf iron, there is no danger that the aluminum section surroundeach iron liner will not expand suflic'iently' to maintain the proper relations of these correlated parts, despite the fact that the iron, steel or bronze is subjected to higher temperatures than thealuminum alloy.

' A motor constructed with cylinders completed in accordance with our process has we now believe, because of the comparative thlnness and uniform cross section of the liners, the intimate contact between said liners and the surrounding walls of the aluminum casting, and the relative efliciency of the aluminum casting in the conducting ,of the heat to the water or cooling agent.

Having described our process, we will now describe a specific construction of a -motor' cylinder made in accordance with our invention.

In the drawings, Figure 1 is a plan view of a flask, after a multi-cylinder casting is made therein, the sand in the flask, casting, cores and chllls thereon being broken away to illustrate the carrying out of the first step of our process.

Fig. 2 is a view of the casting,.partly in side elevation and partly in section.

Fig. 3 is a perspective view of a liner made in accordance with one of the steps of our process.

Fig. 4 is a transverse section through a cylinder section illustrating the step of our process of inserting the liner thereinto.

Fig. 5 is a view similar to Fig. 4, with the liner inserted and a head placed upon the casting and engaging with the upper walls of the liner to hold the latter against outward movement.

In the drawings, 1' indicates as an entirety a flask of suitable construction comprising a drag 1 and a cope 1 in which the molds are made to receive the cores 1 to form the cavity. The mold cavity herein shown is for casting an en bloc four cylinder type of motor. The cores 1 for the cylinder sections are provided with a chill or chills 1. We preferably provide around the sand body constituting the core proper four sectional chills and space them from each other to provide a sand space for the escape of gases and air. The chills 1 are preferably formed from aluminum.

2 indicates the casting, the tubulanor cylindrical walls 2 of which are chilled by the chills 1 and are formed with water jackets 2. The casting is made of aluminum alloy. The cylinder or tubular sections 2 and water jacket?! '2 are formed integral.

After the casting 2. is made and ready for handling, each tubular section 2 thereof may have its inner wall suitably surfaced, if necessary, in order (1) to have such walls concentric with the axis of the cylinder as an entirely of which it forms the outer wall sec tion', and (2) to condition such walls for receivlng and intimately engaging the outer surface of the liner 3, which will be later described.

The surfacing of the inner walls of each cylinder section 2 may be done in any desired manner, as by turning, boring or grinding. V I i In the casting or finishing of each cylinder section 2, we provide a recess 2 at the upper end thereof for a purpose to 'be hereinafter set forth."

Next, we prepare a .tubular liner 3 of iron, steel, bronze or other suitable metal having a flange 3 at the upper end thereof as hereinbefore fully set forth.

Next, we introduce the lower end of a liner into the upper end of a tubular section 2 and then press or force the liner down into the section 2 until the flange on the liner seats itself in the recess 2 in the upper end of the tubular sectionf2 it being understood that the diameters of the internalwalls of the tubular section 2 and the external walls of the liner 3 are such that when the liner is pressed into the tubular section 2 which supports it, intimate engagement of the walls at all points cir'cumferentially where desired throughout that portion traversed by a piston will be effected;

Next, the liner 3 is secured against longitudinal movement. For this purpose we have shown a cylinder head 4c which engages with the upper wall of the flange 3 of the liner. This head may be secured to the casting 2 in any suitable and well known manner (not shown) and when so secured holds the liner against longitudinal movement outwardly, the engagement of the under wall of the flange 3* with the adjacent, wall of the recess 2 serving to prevent the longitudinal movement of the liner inwardly.

To those skilled in the art many modifications of and widely difiering embodiments and applications of our invention will suggest themselves, without departing from the spirit and scope thereof. Our disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting except as indicated by the appended claims.

What we claim is:

1. The art of making a composite internal combustion motor cylinder, which consists in pouring molten aluminum alloy having a low specific gravity and a high coefficient of heat conductivity, in comparison with iron, ilgktlIlSt a core having cylindrical peripheral' 'parts formed of material with a high coefiicient of heat conductivity in comparison with sand, then accurately surfacing the inner cylindrical chilled wall of the resulting casting, and then inserting a tubular liner, of a shape and size to fit within said cylinder section, in' said casting with its outer walls in intimate engagement where desired with said chilled inner cylindrical wall of said casting.

The art of making a composite internal combustion motor cylinder, which consists in pouring molten aluminum alloy having a low specific gravity and a high coefficient of heat conductivity, in comparison with iron, against a core having cylindrical peripheral parts formed of material with a high coefficient of heat conductivity in comparison with sand, then accurately surfacing the inner cylindrical chilled wall of the resulting casting, then forming a tubular liner of a shape and size to fit within said cast cylindrical section and surfacing the internal wall of said liner concentric with its external wall, and then inserting said liner in said casting with its outer wall in intimate engagement where desired with said chilled inner cyindrical wall of the said casting.

3. A composite internal combustion motor cylinder comprising a casting of aluminum alloy having higher coefficients both of heat conductivity and expansion and a lower specific gravity than iron, and formed with a chilled inner cylindrical wall surrounded by means adapted to aid in cooling and accurately surfaced concentrically to the axis of said cylinder, the structure of said chilled wall beingrelatively fine grained and nonporous, and a piston wear resisting tubular liner having its outer walls in intimate engagement where desired with said chilled'cylindrical walls of said castmg.

4. A composite internal combustion motor cylinder comprising a casting of alumiv num alloy having relatively high coefiicients both of'heat conductivity and expansion and a low specific gravity, in comparison with iron, and formedwith a chilled inner cylindrical wall surrounded by means adapted to aid in cooling and accurately surfaced concentrically to the axis of saidcylinder, the structure of said chilled Wall being relativelyfine grained and non-porous, and a piston wear resisting tubular liner of substantially uniform cross-section at any point of its length to be traversed by a piston and having its outer walls in intimate engagement where desired with said chilled cylindrical walls of said casting.

In testimony whereof we aifix our signatures hereto.

EDMUND E. ALLYNE. JOHN WESLEY COLLINS. 

